Expanded clay aggregate and method of preparing the same

An expanded clay aggregate, comprising silica-rich solid waste, iron-rich solid waste, alumina-rich solid waste, magnesia-rich solid waste, and a fluxing agent, the silica-rich solid waste, the iron-rich solid waste, the alumina-rich solid waste, the magnesia-rich solid waste, and the fluxing agent are in a mass ratio of 40-50:10-15:20-30:2-12:3-5, the silica-rich solid waste comprises copper tailings, the iron-rich solid waste comprises red mud, the alumina-rich solid waste comprises fly ash, and the magnesia-rich solid waste comprises magnesite tailings, a content of MgO in the magnesite tailings is greater than 40 wt %, and a chemical composition of the expanded clay aggregate, in terms of mass percentage based on oxides, comprises 45 wt % to 57 wt % of SiO2, 17 wt % to 22 wt % of Al2O3, 6 wt % to 10 wt % of Fe2O3, 2 wt % to 6 wt % of MgO, 5 wt % to 13 wt % of a total amount of Na2O, K2O and CaO, and 4 wt % to 5 wt % of impurity oxides.